This invention generally relates to computer networks. More specifically, this invention relates to devices used for transferring data between computers.
Data transfer networks typically comprise either multiple-port memory devices, such as two-port memories useable by one or two computers, or local area networks which permit many computers to read, write and share data from a common data bus.
A significant limitation of prior art multiple-port memory devices has been the inability to readily accommodate more than two or three computers coupled to the memory. Two-port memory devices are readily available and relatively easy to use but cannot accommodate multiple machines. Memory devices having more than two or three ports are difficult to implement due to the multitude of connections required to serve additional computers. Sharing data among many computers typically requires a more complex system such as a local area network.
A local area network, or LAN as it is known in the art, is a network of computers connected together to share data over a serial data bus. The computers transfer data around the network or ring by each computer receiving a packet of data on the serial bus, decoding the packet to decide if the packet is directed to it, and passing the packet on to the next computer in the network. Local area networks can accomplish a high speed data transfer among many computers but they require relatively complex software overhead to control data transferred around the network.
A need therefore exists for a computer data transfer network implemented substantially or entirely in hardware, thus avoiding complex software overhead, which allows many computers to access data transferred on the network. The ideal high speed data transfer network would combine the most desirable characteristics of both local area networks and multi-port memory devices.